telemetry: Improve perf profiler

build/android/pylib/perf/perf_control_unittest.py

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import sys
+import unittest
+
+sys.path.append(os.path.join(os.path.dirname(__file__), os.pardir, os.pardir))
+
+from pylib import android_commands
+from pylib.device import device_utils
+from pylib.perf import perf_control
+
+
+class TestPerfControl(unittest.TestCase):
+  def setUp(self):
+    if not os.getenv('BUILDTYPE'):
+      os.environ['BUILDTYPE'] = 'Debug'
+
+    devices = android_commands.GetAttachedDevices()
+    self.assertGreater(len(devices), 0, 'No device attached!')
+    self._device = device_utils.DeviceUtils(
+        android_commands.AndroidCommands(device=devices[0]))
+
+  def testForceAllCpusOnline(self):
+    perf = perf_control.PerfControl(self._device)
+    cpu_online_files = self._device.old_interface.RunShellCommand(
+        'ls -d /sys/devices/system/cpu/cpu[0-9]*/online')
+    try:
+      perf.ForceAllCpusOnline(True)
+      for path in cpu_online_files:
+        self.assertEquals('1',
+                          self._device.old_interface.GetFileContents(path)[0])
+        mode = self._device.old_interface.RunShellCommand('ls -l %s' % path)[0]
+        self.assertEquals('-r--r--r--', mode[:10])
+    finally:
+      perf.ForceAllCpusOnline(False)
+
+    for path in cpu_online_files:
+      mode = self._device.old_interface.RunShellCommand('ls -l %s' % path)[0]
+      self.assertEquals('-rw-r--r--', mode[:10])
+
+
+if __name__ == '__main__':
+  unittest.main()